<template>
  <div class="component-upload-image">
    <el-upload
      multiple
      :action="uploadImgUrl"
      list-type="picture-card"
      :on-success="handleUploadSuccess"
      :before-upload="handleBeforeUpload"
      :limit="limit"
      :on-error="handleUploadError"
      :on-exceed="handleExceed"
      ref="imageUploadRef"
      :on-remove="handleDelete"
      :show-file-list="true"
      :headers="headers"
      :file-list="fileList"
      :on-preview="handlePictureCardPreview"
      :class="{ hide: fileList.length >= limit }"
    >
      <el-icon><Plus /></el-icon>
    </el-upload>

    <!-- 上传提示 -->
    <div class="el-upload__tip" v-if="showTip">
      请上传
      <template v-if="fileSize">
        大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b>
      </template>
      <template v-if="fileType">
        格式为 <b style="color: #f56c6c">{{ fileType.join('/') }}</b>
      </template>
      的文件
    </div>

    <el-dialog
      v-model="dialogVisible"
      title="预览"
      width="800"
      append-to-body
      :close-on-click-modal="false"
    >
      <img :src="dialogImageUrl" style="display: block; max-width: 100%; margin: 0 auto" />
    </el-dialog>
  </div>
</template>

<script setup lang="ts">
import { ref, watch, computed, reactive } from 'vue'
import { getToken } from '@/utils/auth'
import {
  type UploadProps,
  type UploadInstance,
  type UploadFile,
  type UploadRawFile,
  ElMessage,
} from 'element-plus'
import env from '@/utils/env'
import { useLoading } from '@/composables/useLoading'

// 定义属性
interface Props {
  value?: string | object | Array<string | object> | null
  // 图片数量限制
  limit?: number
  // 大小限制(MB)
  fileSize?: number
  // 文件类型, 例如['png', 'jpg', 'jpeg']
  fileType?: string[]
  // 是否显示提示
  isShowTip?: boolean
}

const props = withDefaults(defineProps<Props>(), {
  value: null,
  limit: 5,
  fileSize: 5,
  fileType: () => ['png', 'jpg', 'jpeg'],
  isShowTip: true,
})

const emit = defineEmits(['input', 'update:value'])

const loading = useLoading()

// 数据定义
const number = ref(0)
const uploadList = ref<{ name: string; url: string }[]>([])
const dialogImageUrl = ref('')
const dialogVisible = ref(false)
const imageUploadRef = ref<UploadInstance>()
const uploadImgUrl = env.VITE_APP_BASE_API + '/file/upload' // 上传的图片服务器地址

const headers = reactive({
  Authorization: 'Bearer ' + getToken(),
})

const fileList = ref<UploadFile[]>([])

// 计算属性
const showTip = computed(() => {
  return props.isShowTip && (props.fileType || props.fileSize)
})

// 监听value变化
watch(
  () => props.value,
  (val) => {
    if (val) {
      // 首先将值转为数组
      const list = Array.isArray(val) ? val : String(val).split(',')
      // 然后将数组转为对象数组
      fileList.value = list.map((item) => {
        if (typeof item === 'string') {
          item = { name: item, url: item } as UploadFile
        }
        return item as UploadFile
      })
    } else {
      fileList.value = []
    }
  },
  {
    deep: true,
    immediate: true,
  },
)

// 方法定义
// 上传前loading加载
const handleBeforeUpload: UploadProps['beforeUpload'] = (file: UploadRawFile) => {
  let isImg = false
  if (props.fileType && props.fileType.length) {
    let fileExtension = ''
    if (file.name.lastIndexOf('.') > -1) {
      fileExtension = file.name.slice(file.name.lastIndexOf('.') + 1)
    }
    isImg = props.fileType.some((type) => {
      if (file.type.indexOf(type) > -1) return true
      if (fileExtension && fileExtension.indexOf(type) > -1) return true
      return false
    })
  } else {
    isImg = file.type.indexOf('image') > -1
  }

  if (!isImg) {
    ElMessage.error(`文件格式不正确，请上传${props.fileType?.join('/')}图片格式文件!`)
    return false
  }
  if (file.name.includes(',')) {
    ElMessage.error('文件名不正确，不能包含英文逗号!')
    return false
  }
  if (props.fileSize) {
    const isLt = file.size / 1024 / 1024 < props.fileSize
    if (!isLt) {
      ElMessage.error(`上传头像图片大小不能超过 ${props.fileSize} MB!`)
      return false
    }
  }
  loading.showLoading('正在上传图片，请稍候...')
  number.value++
  return true
}

// 文件个数超出
const handleExceed: UploadProps['onExceed'] = () => {
  ElMessage.error(`上传文件数量不能超过 ${props.limit} 个!`)
}

// 上传成功回调
const handleUploadSuccess: UploadProps['onSuccess'] = (res, file) => {
  if (res.code === 200) {
    uploadList.value.push({ name: res.data.url, url: res.data.url })
    uploadedSuccessfully()
  } else {
    number.value--
    loading.closeLoading()
    ElMessage.error(res.msg)
    imageUploadRef.value?.handleRemove(file)
    uploadedSuccessfully()
  }
}

// 删除图片
const handleDelete: UploadProps['onRemove'] = (file) => {
  const findex = fileList.value.map((f) => f.name).indexOf(file.name)
  if (findex > -1) {
    fileList.value.splice(findex, 1)
    emit('input', listToString(fileList.value))
    emit('update:value', listToString(fileList.value))
  }
}

// 上传失败
const handleUploadError: UploadProps['onError'] = () => {
  ElMessage.error('上传图片失败，请重试')
  loading.closeLoading()
}

// 上传结束处理
const uploadedSuccessfully = () => {
  if (number.value > 0 && uploadList.value.length === number.value) {
    fileList.value = fileList.value.concat(
      uploadList.value.map((item) => ({ name: item.name, url: item.url }) as UploadFile),
    )
    uploadList.value = []
    number.value = 0
    emit('input', listToString(fileList.value))
    emit('update:value', listToString(fileList.value))
    loading.closeLoading()
  }
}

// 预览
const handlePictureCardPreview: UploadProps['onPreview'] = (file) => {
  dialogImageUrl.value = file.url!
  dialogVisible.value = true
}

// 对象转成指定字符串分隔
const listToString = (list: UploadFile[], separator?: string) => {
  let strs = ''
  separator = separator || ','
  for (const i in list) {
    if (list[i]?.url) {
      strs += list[i].url + separator
    }
  }
  return strs != '' ? strs.substr(0, strs.length - 1) : ''
}
</script>

<style scoped lang="scss">
// .el-upload--picture-card 控制加号部分
:deep(.hide .el-upload--picture-card) {
  display: none;
}
// 去掉动画效果
:deep(.el-list-enter-active),
:deep(.el-list-leave-active) {
  transition: all 0s;
}

:deep(.el-list-enter, .el-list-leave-active) {
  opacity: 0;
  transform: translateY(0);
}
</style>
